Heretofore, carbonated drinks for home consumption have normally been purchased in bottles after carbonated water and syrup have been mixed in a large tank and the mixture inserted into the bottles. This procedure of supplying drinks for consumption is quite expensive since the majority of a carbonated drink is water. As a result, each bottle contains only a relatively few drinks. The cost of the bottle and the expense in delivering the large volume of water contained in each drink adds substantial expense to each individual drink.
In an attempt to reduce the overall cost per drink, bars, restaurants, and other similar establishments utilize postmixed beverage dispensing systems wherein syrup from large containers is mixed at the establishment with carbonated water for producing drinks. While the large volume or commercial postmixed beverage dispensing systems have worked satisfactorily in establishments that have a high drink volume, they are not practical for in-home use or in use in establishments which have a relatively low volume of drink consumption. The commercial beverage dispensing devices are quite expensive utilizing relatively large carbon dioxide bottles and syrup containers making it quite impractical to utilize in low volume establishments such as homes. Furthermore, the syrup container utilized in the commercial postmixed beverage dispensing equipment require mechanical couplings to be engaged and disengaged when inserting and removing the syrup container therefrom.
In U.S. Pat. No. 3,685,694 granted to Frank M. Iannelli on Aug. 22, 1972 an attempt was made to provide a syrup container which is pierced by piercing pins upon insertion of the container in a receptacle. One of the piercing pins is connected to a CO.sub.2 line which is used for pressurizing the container and another piercing pin provides an outlet for the liquid from the container. Upon opening of a valve for dispensing a carbonated drink from the equipment, carbon dioxide gas previously introduced into the sealed container through the CO.sub.2 pin, forces liquid syrup to a mixing head, where it is mixed with the carbonated water which is simultaneously supplied to the mixing head. One problem with the device shown in U.S. Pat. No. 3,685,694 is that the pin for the carbon dioxide gas is normally below the liquid level of the syrup. As a result, when the carbon dioxide tank becomes exhausted, the syrup tends to flow back through the CO.sub.2 piercing pin into the CO.sub.2 line. This, of course, contaminates the CO.sub.2 line. In order to prevent the backflow of syrup into the CO.sub.2 line a check valve has been utilized in the line, however, the syrup coming into contact with the check valve frequently fouls the check valve causing malfunctions.